After six years, development on Window Maker has picked up again. Other than mere bug fixes, the two new releases (so far) also include lots of code cleanup and, yes, new features as well. Welcome back!

As it happens I've been using this WM on Debian Squeeze PPC, on an *ahem* "ancient" 800 MHz Powerbook G4, and it works great; much faster than any other floating WM I've tried. Only misfeature IMO is that you have to edit the menu if you want to create keybindings to launch stuff.

Couldn't say; last time I tried Ubuntu I discovered that it did not include the driver for the Powerbook's IDE controller. Shame. At any rate Debian works pretty well, though applications can be pretty sluggish. (GTK2 and Qt4 are both godawful slow on old computers!)

Note however that the Powerbook's hard drive seems to be slowly failing, so observations about performance may be significantly skewed.